This application claims priority to an application entitled xe2x80x9cInterface Connection Cable Antenna And Antenna Diversity Device Of Mobile Communication Terminal Using The Samexe2x80x9d filed with the Korean Industrial Property Office on Nov. 27, 2001 and assigned Serial No. 2001/74378, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an antenna structure of a mobile communication terminal, and in particular to an interface connection cable antenna and an antenna diversity device of a mobile communication terminal for transmitting and receiving data using the interface connection cable antenna.
2. Description of the Related Art
In accordance with recent development of communication industries, high-speed data rate (HDR) services capable of achieving an improvement in the quality of ultrahigh-speed wireless internet services under the condition in which they are connected with the code division multiple access (CDMA) 2000-1X are being prepared by some mobile communication service providers. Although HDR services do not support voice services, they have a superior data transfer ability to that of existing cable ultrahigh-speed internet services.
HDR services available for CDMA 2000-1X EVDO (Evolution Data Only) services, known as an ultrahigh-speed wireless data communication using a second generation mobile communication network, are classified as a synchronous IMT (International Mobile Telecommunication)-2000 (3G: 3rd Generation) because they have a transfer speed 10 times or more than of the CDMA 2000-1X (IS95C), considered as a 2.5th Generation. Such an HDR scheme is suitable for ultrahigh-speed wireless internet services in that channels dedicated for data are assigned to provide a data rate of 2.4 Mbps at maximum on a forward channel, and a data rate of 153.6 Kbps at maximum on a reverse channel. HDR services may be used to improve the data transfer ability in existing CDMA 2000-1X (IS95C) networks or individual data networks. In existing CDMA networks, part of voice channels are changed into data channels. However, although the HDR scheme allows each channel to be shared by several users in accordance with a combination of a time division multiplexing (TDM) scheme and the CDMA scheme, each user is not allocated with a fixed time slot for the channel, as compared to a time division multiple access (TDMA) scheme. In accordance with the HDR scheme, each user is allocated with the channel only when the channel is to be used. The data rate of HDR optimized for IP (Internet Protocol) packets and Internet access may vary depending on the distance from a mobile communication terminal to a base station.
Accordingly, mobile communication terminals supporting EVDO services can provide services at a data rate of 2 Mbps or more, surpassing that of the cable ultrahigh-speed internet services, so that it is possible to achieve transmission and reception of moving pictures in a real time fashion. Such a mobile communication terminal uses a space diversity scheme using two antennas. That is, this mobile communication terminal has two wireless receiving units in order to minimize loss of receiving information caused by fading. However, a large part of currently available mobile communication terminals have only a single antenna. In this case, where it is desired to implement the space diversity using two antennas, a separate antenna should be installed. However, there is a difficulty in installing such separate antenna because mobile communication terminals have a compact size.
Although the desired space diversity can be implemented in a mobile communication terminal by installing a chip antenna in the mobile communication terminal in a built-in fashion,. in this case, however, the chip antenna exhibits a degraded standing wave ratio. As a result, it is impossible to provide effective high-speed data transmission and reception services to users.
Therefore, an object of the invention is to provide an external interface connection cable antenna of a mobile communication terminal provided with a diversity antenna.
Another object of the invention is to provide an antenna diversity device of a mobile communication terminal for high-speed data communication services, which can easily implement a desired space diversity using an interface connection cable antenna.
Another object of the invention is to provide an interface connection cable antenna installed between a mobile communication terminal and a data terminal (for example, a computer) to transmit data at high speed, which is capable of easily implementing a desired space diversity in the data transmission.
In accordance with one aspect, the present invention provides an interface connection cable antenna comprising: a plug pin plate to be coupled to an external interface connector included in a mobile communication terminal; an interface plug embedding therein an antenna plug to be coupled to an antenna connector included in the mobile communication terminal; an antenna connected to the antenna plug via the interface plug, the antenna having a desired length; and an interface cable connected at one end thereof to a connector coupled to a data port included in an external terminal while being provided at the other end thereof with at least one wire connected to the plug pin plate via the interface plug.
The antenna may comprise a wire antenna or a loop antenna having a desired length. Alternatively, the antenna may comprise a helical antenna made of a wound coil and embedded in a housing included in the interface plug. The helical antenna may have a structure allowing the helical antenna to be used in a state coupled with a whip.
In accordance with another aspect, the present invention provides an interface connection cable antenna comprising: a plug pin plate to be coupled to an external interface connector included in a mobile communication terminal; an interface plug embedding therein an antenna plug to be coupled to an antenna connector included in the mobile communication terminal; and an interface cable connected at one end thereof to a connector coupled to a data port included in an external terminal, the interface cable including at least one data cable connected to the plug pin plate via the interface plug at the other end of the interface cable, a cable antenna made of a conductive material and arranged around the data cable, the cable antenna being connected to the antenna plug, and a coating layer adapted to protect the cable antenna from surroundings.
A shield layer may be formed between the data cable and the cable antenna in the interface cable.
The antenna may comprise a wire antenna having a desired length or a helical antenna made of a wound coil.
In accordance with another aspect, the present invention provides an antenna diversity device for use in a mobile communication terminal including a terminal body, a first radio frequency part received in the terminal body and adapted to perform transmission and reception of data, and a second radio frequency part for receiving data under a desired control, comprising: an interface connection part interfaced with an external terminal for data communications; an external antenna connector; a switch connected between the external antenna connector and the second radio frequency part, the switch serving to switch on/off the connection between the external antenna connector and the second radio frequency part in response to a switching control signal inputted thereto; a controller connected to the interface connection part, and adapted to sense a connection to an interface cable, thereby supplying the switching control signal to the switch; and the interface cable provided with an antenna connected to an antenna plug coupled to the external antenna connector, and adapted to connect the interface connection part to a data communication port of the external data communication terminal.
The antenna diversity device having the above described configuration for use in a mobile communication terminal operates to receive data at high speed while implementing a desired space diversity by an antenna mounted to the body of the mobile communication terminal and the interface connector cable antenna when the interface connector cable antenna is coupled to the interface connector part of the mobile communication terminal under an HDR service mode.